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Direct measurement of sub-surface mass change using the variable-baseline gravity gradient method

Geophysical Research Letters

By:
, , , ,
DOI: 10.1002/2014GL059673

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Abstract

Time-lapse gravity data provide a direct, non-destructive method to monitor mass changes at scales from cm to km. But, the effectively infinite spatial sensitivity of gravity measurements can make it difficult to isolate the signal of interest. The variable-baseline gravity gradient method, based on the difference of measurements between two gravimeters, is an alternative to the conventional approach of individually modeling all sources of mass and elevation change. This approach can improve the signal-to-noise ratio for many applications by removing the contributions of Earth tides, loading, and other signals that have the same effect on both gravimeters. At the same time, this approach can focus the support volume within a relatively small user-defined region of the subsurface. The method is demonstrated using paired superconducting gravimeters to make for the first time a large-scale, non-invasive measurement of infiltration wetting front velocity and change in water content above the wetting front.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Direct measurement of sub-surface mass change using the variable-baseline gravity gradient method
Series title:
Geophysical Research Letters
DOI:
10.1002/2014GL059673
Volume
41
Issue:
8
Year Published:
2014
Language:
English
Publisher:
American Geophysical Union
Contributing office(s):
Arizona Water Science Center
Description:
8 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Geophysical Research Letters
First page:
2827
Last page:
2834
Number of Pages:
8